Square bottom bag



Jafl- 25, 1966 A. .1. clvlTELLo 3,231,173

SQUARE BOTTOM BAG original Filed March 9, 1959 3 Sheets-Sheet 1 Anf/:any J. Glv/e//OINVENTOR Jan. 25, 1966 A. J. CIVITELLO 3,231,173

SQUARE BOTTOM BAG Original Filed March 9, 1959 3 Sheets-$11681. 2

Anfhony J. Civ/fe//o 1 N VE N TOR BY Y), x ?7\* Quiz 27 ATTORNEY Jan. 25, 1966 A. J. clvrrELLo 3,231,173 SQUARE BOTTOM BAG Original Filed March 9, 1959 5 Sheets-Sheet 31 Anf/ron] J. Civ/'fella INVENTOR ATTORNEY United States Patent O 3,231,173 SQUARE ETTOM BAG Anthony J. Civitello, Malvern, Pa., assigner to Continental Can Company, Inc., New York, NX., a corporation of New York Continuation of abandoned application Ser. No. 797,970, Mar. 9, 1959. This application Oct. 16, 1964, Ser. No.

13 Claims. (Cl. 22g- 59) Lucts which contain oil or grease inasmuch as contact of the exposed raw edges of the paper bag bottom with the product is not eliminated. it is, therefore, the primary object of this invention to provide an improved bag construction of the type which includes an outer member in the form of a wrapper and an inner member in the form of a liner for the wrapper, the two being combined to form a bag with the interior of the bag being completely dened by the liner whereby no portion of the wrapper may come into Contact with the product in order that the bag, when formed with a grease-proof liner may be particularly adapted to the packaging of products containing oil and grease.

Another object of this invention is to provide a bag of the type which includes an outer wrapper and an inner liner, the liner having material taken away from the top edge thereof with such material being utilized at the bottom edge thereof in such a manner that the liner extends below the bottom edge of the wrapper, and when the liner and wrapper are folded into the bag shape, the wrapper not only completely underlies the material of the wrapper at the bottom of the bag but also certain of the materials of the liner overlie portions of the wrapper whereby the entire interior of the bag is defined by the liner and an ettective seal is attained between the liner and the wrapper and the bottom of the bag whereby the same amount of material normally used in forming a light bag is required and at the same time the additional sealing protection is obtained.

Another object of this invention is to provide an improved bag construction of the type which includes a liner and a Wrapper, the liner being so constructed whereby when the bottom of the bag is formed, the liner is disposed innermost and protects all edges of the wrapper so that the possibilty of edges of the wrapper being exposed to the interior of the bag is eliminated, the portions of tie liner forming the bottom of the bag being sealed relative to each other to form a liner which is provided with a seal separate and independent of the seal of the wrapper, which seal is reinforced by the seal of the wraper so that a bag having a completely sealed bottom is provided, which bag may be used for storing an air-tight relation product such as coffee, which products are considered perishable products, thereby increasing the shelflife of these products.

A further object of this invention is to provide a new bag construction of the type which includes a liner and a wrapper, the construction of the bottom of the bag being such that the liner is completely sealed by itself to form an inner bottom, and the wrapper is additionally sealed to form an outer bottom, the wrapper seal supplementing the liner seal so as to assure the sealing of the bottom to a degree whereby the bag is both sift-proof l 3,231,173 Patented Jan. 25, lti

ice

and grease-proof and may be used in the packaging of materials, such as insecticides, which materials cannot in most cases be packaged in normally constructed bags.

Another object of this invention is the provision of an improved blank construction from which a lined bag may be formed, the blank construction including an outer or wrapper-forming blank and an inner or liner forming blank, the two blanks having substantially the same amount of material, but the inner blank having offset bottom edges projecting beyond the outer blank, the materials for the bottom edges being taken away from the upper edges of the inner blank whereby the outer material required in the blank for forming the desired seal at the bottom of the bag is obtained from where it is not needed and placed to the ultimate use in the bag construction.

Another object of this invention is to provide an improved method of forming a bag of the lined type, the method including the steps of providing inner and outer blanks wherein the inner blank is provided with projecting bottom edge portions, marginally securing the blanks together in transversely offset relations, folding andsecuring together longitudinal edges of the blank to form a tube which includes an inner tube and an outer tube, the bottom portions of the blanks being so slit whereby when the bottom portion of the tube is folded to form the bag, the material of the inner blank completely underlies the material of the outer blank so that the bottom includes an inner portion completely defined by the inner blank as well as an outer portion completely defined by the outer blank.

Another object of this invention is to provide a bag constructed of the type which is readily adaptable to both the construction of a square bottom bag and a Satchel bag.

At the present time many of the bags designed to package products in a sealed relation include a liner which must be heat-sealed to provide the .desired seal. Since the heat sealing of a bag involves a specific time element to obtain the desired heat-seal, such a construction is not readily adaptable to high production speeds. It is, therefore, a further object of this invention to provide a bag which is of an all-glued construction, the bag being formed through the use of proper adhesives with both the liner of the bag and the wrapper of the bag `being sealed with respect to each other through the use of the adhesive to provide the same amount of protection as a `heat-sealezd bag and at the same time retaining all of the advantages of high production speeds which `can be obtained by the use of adhesives.

With the above and other objects in view that will hereinatter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a plan vieW of the blank assembly for forming the bag, the wrapper-forming blank overlying the liner-forming blank and being shown in dotted lines in order to illustrate the Idetails of both blanks and the relationship of the blanks when secured together prior to the formation of the bag.

FGURE 2 is a planview of the tube formed from the blank in the initial bag forming operation, the upper end of the tube being broken away.

FIGURE 3 is a plan view similar to FiGURE 2 and shows the bottom of the bag after the diamond folds have been formed therein.

FIGURE 4 is a plan viewsimilar to FlGURE 3 and .shows the ilaps of the bottom of the bag folded inwardly.

FIGURE 5 is a bottom `plan view similar to FIGURE 4 and shows the bottom of the bag after the adhesive has been applied thereto.

FIGURE 6 is an enlarged plan view of the lower portion of the bag after a first one of the tabs has been folded into position.

FIGURE 7 is an enlarged plan view similar to FIG- URE 6 showing the completed bag bottom.

FIGURE 8 is an enlarged section on the line 8 3 of FIGURE 7.

FIGURE 9 is van enlarged fragmentary plan view of the bottom portion of a Satchel-type bag.

Referring more particularly to the drawings, wherein similar reference characters designate like parts throughout the several views, in FIGURE 7 there is illustrated the square bottom bag which is a preferred form of the invention and which is referred to in general by the reference numeral 1. The square bottom bag 1 is formed from a blank assembly which is best illustrated in FIGURE 1 and is referred to in general by the reference numeral 2. The blank assembly 2 includes a blank 3 which defines the Wrapper or outer tube member of the square botom bag 1, and a blank 4 which defines the liner or inner tube member of the square bottom bag 1.

In FIGURE 1 the blanks 3 and 4 are illustrated in overlying relation secured together. For purposes of clarity the blank 3 is illustrated in dotted lines. The blank 3 is rectangular in outline and preferably has a square cut upper edge 5 although it may be provided with a thumb opening (not shown). The blank 3 also has a lower or bottom edge 6 which edge has opening therethrough pairs of longitudinally extending slits 7 and 8, and 9 and 10. The slits 7 and 8 define a tab 11. The slits 9 and 19 define an identical tab 12. Disposed intermediate the tabs 11 and 12 is a liap 13. A similar flap 14 extends between the left edge 15 of the blank 3, `as viewed in FIGURE l and the slit 7. The blank 3 also has a right edge 16 which, together with the slit defines a flat portion 17.

The blank 4, like the blank 3, is generally rectangular in outline. It is to be noted that when the blanks 3 and `4 are secured together to form the blank assembly 2, the

blanks 3 and 4 are transversely offset so that the blank 4 extends to the left of the blank 3 and the blank 3 extends to the right of the blank 4. The blanks 3 and 4 are substantially of the same width.

The blank 4 has an upper edge 13 which is interrupted by cutouts 19 and 20. The blank 4 also has a bottom edge 21 which includes projections 22 and 23. The projections 22 and 23 correspond to the cutouts 19 and 20 so that there is no loss of material in forming the blank 4. The material required for the projections 22 and 23 is sacrificed from the upper portion of the blank 4.

The blank 4 is provided with longitudinal slits 24, and 25 which extend along the edges of the projection 22 and define a flap 26. The bottom edge of the blank 4 is provided With a second pair of longitudinally extending slits 27 and 28 which extend along the edges of the projection 23 and define a flap 29. It is to be noted that the aps 26 and 29 overliethe iiaps 14 and 13, respectively, and are of a greater width than their respective flaps.

In the formation of the flaps 26 and 29, there is also formed a tab 30 which is disposed intermediate the slits 25 and 27. The slit 24, together with a lefthand edge 31 of the blank 4, defines a tab portion 32. The slit 28, together with the righthand edge 33 of the blank 4 defines a tab portion 34. After the blanks 3 and 4 have been formed, they are secured together by lines of adhesive, the lines 36, 37 and 38. The line of adhesive 36 extends along the bottom edge of the blank 33 -along the flap 14, down the side edge of the blank 3, across the upper edge of the blank 4 around the cutouts 19 and 20, then along the right edge 33 of the blank 4, across the bottom edge of the blank 3 along the tab portion 34 and terminating parallel to the slit 2S. The line of adhesive 37 is generally channel-shaped in outline and extends generally about the periphery of the tab 30. The third lin-e of adhesive 38 is in the form of a straight line of adhesive extending along the bottom edge of the blank 3 in the vicinity of the iiaps 13 and 29. Thus, for all practical purposes the blanks 3 and 4 are marginally secured together in sealed relation to form the blank assembly 2.

The blank assembly 2 has formed thereon longitudinally extending fold lines 39 and 40. The fold line 39 extends along the longitudinal centers of the flaps 14 and 26 whereas the fold line 40 extends along the longitudinal centers of the aps 13 and 29. Extending transversely of the blank assembly 2 adjacent the bottom edge thereof is a pair of fold lines 41 and 42. The fold line 42 is disposed the furthest from the bottom edge of the blank assembly 2 and extending from the point of intersection between the fold lines 39 and 42 to the upper end of the slit 24 is a diagonal fold line 43. A similar diagonal fold line 44 extends from the inner section of the fold lines 39 and 42 to the upper end of the slit 25. It is to be noted that the slit 7 terminates at its inner section with the fold line 44.

Extending from the inner section of the fold lines 43 and 42 is a diagonal fold line 45 whose opposite end terminates `at the upper end of the slit 27 A similar diagonal fold line 46 extends from the inner section of the fold lines 40 and 42 to the upper end of the slit 28. The slit 8 terminates at its upper end at its inner section with the fold line 45 and the slit 9 terminates at its upper end at its inner section with the fold line 46.

The blank assembly 2 also includes additional longi tudinally extending fold lines in the form of fold lines 47, 48, 49 and 50. The fold line 47 extends from the inner section of the fold line 43 and the fold line 41. The fold line 48 extends from the inner section of the fold lines 41 and 42. The fold lines 47 and 48 cooperate with the fold line 49. The fold line 49 extends from the inner section of the fold lines 41 `and 4S whereas the fold line 5t) extends from the inner section of the fold lines 41 and 46. The fold lines 49 and 50 cooperate with the fold line 40.

In the initial formation of the square bottom bag 1, the blank assembly 2 is folded to form elongated tube which is best illustrated in FIGURE 2 and is referred to in general by the reference numeral 511. The tube 51 has a cross-section best illustrated in FIGURE 8. In the formation of the tube 51, the lblank 3 becomes a wrapper or outer tube member 52. 'Ilhe blank 4 becomes a liner or inner tube member 53. It is to be noted that the side edges of the blanks 3 and 4 are dis/posed in overlapping relation so that the liner 53 completely underlies the wrapper 52 at all points except in the vicinity of the cutouts 20 and 19. In the formation of the tube 51, there are formed oppositely facing walls 54 and 56 which are connected together :by accordion pleat portions 57 and 58.

As is best illustrated in FIGURE 2, in the formation of the tube 51, the projection 23 is folded back over and outwardly of the flap 13. On the other hand, the projection 22 continues to project beyond the Hap 14. In the formation of the tube 51, the fiap portion is secured to the flap 14 and the fold line 59 defining the upper end of the flap portion 17 is aligned with the fold line 43. Also the tab portions 32 and 34 are adhesively secured together to form a single tab.

After the tube 51 has been formed, the bottom portion of the tube 51 is folded to form diamond folds 60 and 61 at which time the tabs and the aps of the blank assembly 2 are disposed in upstanding rectilinear relation. This is best illustrated in FIGURE 3. As the folding of the bottom portion of the tube 51 continues, the iiaps 13 and 20 are folded inwardly as a unit and then the flaps 14 and 26 are folded inwardly as a unit, as is best illustrated in FIGURE 4. y

At this time it is pointed that the flaps 13 and 14 have dimensions extending transversely of the bottom of the bag 1 each of which is substantially equal to one-half of the width of the bottom bag 1. As a result, the opposed edges of the flaps 13 and 14 are substantially in edge abutting relation. However, inasmuch as the flaps 26 and 29 include the projections 22 and 23, respectively, even though the projection 23 is folded back over the tlap 13, the projection Z2 extends beyond the flap 14 and directly overlie the projection 23.

After the bottom of the bag 1 has been folded to the condition illustnated in FIGURE 4, adhesive 62 is applied in the pattern illustrated in FIGURE 5. This adhesive 62 is applied entirely over the tabs 11 and 30, along the lines of juncture between the flaps 13 and 14, including over the projections 22 and 23, The adhesive 62 is also disposed along lines parallel to the edges of the tabs 11 and 12, but slightly inwardly thereof. These lines of adhesive terminate along the fold line 41 and are referred to by the reference numerals 63 and 64. Extending transversely between the lines 63 and 6d of adhesive 62 is a transverse line 65 of adhesive which corresponds generally to the position of the free end of the tab 12.

After the adhesive 62 has been applied the folding of the bottom of the bag 1 continues. The tab 12 and the tab portions 32 and 34 are folded over as a unit into a position overlying the flaps 13 and 14 and are secured in place by the adhesive lines 63, 64 and 65. This is best shown in FIGUURE 6. Finally, the tabs 11 and 30 are folded over along the fold line 41 as a unit to corn- -plete the bottom of the bag 1, the bottom being referred to by the reference numeral 66. It is to be noted that the tab 11 overlies the tab 12.

In the formation of the bottom 66, in view of the fact that the projections 22 and 23 directly overlie each other and the joint therebetween is further overlaid by the tab portions 32 and 34 and the tab 30, the liner S3 is sealed entirely independently of the wrapper 52. Thus, rwith the exception of the areas of the wrapper 52 in the vicinity of the cutouts 19 and 20, no portion of the wrapper is exposed to the interior of the bag 1. Inasmuch as the product to be packed in the bag 1 will not contact this area of the bag, it will be apparent that the liner 53 completely protects the product to be packaged from the wrapper S2.

lt is to be understood that the composition of the wrapper 52, as well as the composition of the liner 53, will vary depend-ing upon the particular product to be .packaged in the blag 1. If greasy products, such as cookies or the like, are to be packaged, the wrapper 52 will be formed of a suitable paper product and may have the exterior surface thereof covered with printed matter. The liner 53 will be formed of a suitable glassine materi'al. On the other hand, if the bag 1 is to receive powdered materials, it is not necessary that the Wrapper 53 be formed of a grease-proof material. At this time it is pointed out that the construction of the bag 1 is such that it is, for all practical purposes, sift-proof inasmuch as a rst completely sealed liner is formed and then a corn- :pletely sealed wrapper is for-med, the two hav-ing joints entirely independent of each other but cooperating with each other to form a sift-proof bottom 66. It is also pointed out at this time that the bag 1 is not limited in construction to two plies, but may be of the desired number of plies. This is accomplished by providing additional blanks, such as the blanks 3 and 4, where deemed necessary.

The bag construction is also not limited to a square bottom bag, such as the bag 1, but may be readily adapted to a Satchel-type bag. A bag of this type is illustrated in FIGURE 9 and is referred to by the reference numeral 67. The bag 67 has a bottom 68. The bag 6'7 may be formed from the same blank assembly as the bag 1 with the exception of a minor difference in the fold lines. The bottom 68 will be identical in sealing qualities to the bag 66 and will differ therefrom only in that the diamond folds 60 and 61 will be eliminated in the folding of the bottom 68. Like the bag 1, the Satchel-type bag 67, may be formed of any desired materials and may be formed in plies in excess of two.

From the foregoing, it will be apparent that there has been devised a bag construction of the conventional type, either a square bottom bag or a Satchel-type bag, wherein a liner is so congurated whereby it may be formed without the loss of any material whatsoever and at the same time the liner will be so related to the wrapper whereby a separate seal between all components of the liner may be obtained so that the liner is separate and independent of the wrapper for the sealing qualities of the bags. While two preferred forms of blags have been shown and described, it is to be understood that various changes and improvements may be made without departing from the scope and spirit of the appended claims.

l claim:

1. A bag formed of a flattened composite tube including at least an outer tube land an inner tube, said flattened composite tube having a pair of oppositely facing walls and a bottom end, a pair of symmetrically disposed longitudinally extending slits in the bottom end of each of said walls defining tabs and flaps on said outer and inner tubes, the spacing of the slits in said inner tube being lesser than the spacing of the slits in the outer tube whereby said inner tube flaps are of a greater Width than said outer tube flaps and said inner tube tabs are of a lesser width than said -outer tube tabs, said inner tube flaps having bottom edges disposed beyond the bottom edges of said outer tube flaps to form projecting bottom portions, the projecting bottom portion of one of said inner tube flaps being reversely folded over the bottom edge tof an associated one of said outer tube flaps, upwardly diverging fold lines on each of said walls separating said flaps and tabs, said slits terminating at said fold line, said flaps being first folded towards each other, said outer tube flaps each extending substantially half way across the length of the bag bottom, the projecting bottom portion of the other of said inner tube flaps overlying said reversely folded bottom portion, said tabs extending more than half way across the width of the bag bottom in overlapping relation to each other and to said iiaps whereby said inner tube flaps and tabs are sealed to each -other exclusive of said outer tube, and said outer tube flaps and tabs overlie and protect the joints between said inner tube ilaps and tabs and all interior portions of the bag bottom are formed by said inner tube.

2. A bag formed of a flattened composite tube including at least an outer tube and an inner tube, said flattened composite tube having a pair of oppositely facing walls and a bottom end, a pair of symmetrically disposed longitudinally extending slits in the bottom end of each of said walls defining tabs and flaps on said outer and inner tubes, the spacing of the slits in said inner tube being lesser than the spacing of the slits in said outer tube whereby said inner tube flaps are of a greater width than said outer tube iiaps and said inner tube tabs are of a lesser width than said outer tube tabs, said inner tube flaps having bottom edges disposed beyond the bottom edges of said outer tube ilaps to form projecting bottom portions, the projecting bottom portion of one of said inner tube flaps being reversely folded over the bottom edge of an associated one of said outer tube aps, upwardly diverging fold lines on each of said walls separating said flaps and tabs, said slits terminating at said fold line, said flaps being first folded towards each other, said outer tube flaps each extending substantially half way across the length of the bag bottom, the projecting bottom portion of the other of said inner tube" flaps overlying said reversely folded bottom portion, said tabs extending more than half way across the width of the bag bottom in overlapping relation to each other and to said iapsI whereby said inner tube flaps and tabs are sealed to each other exclusive of said outer tube, and said outer tube flaps and tabs overlie and protect the joints between said inner tube ilaps and tabs `and all interior portions of the bag bottom are formed by said inner tube, said outer tube being formed from a rectangular blank, said inner tube being formed from a blank having substantially the same area as said outer tube blank.

3. A bag formed of a flattened composite tube including at least an outer tube and an inner tube, said flattened composite tube having a pair of oppositely facing walls and a bottom end, .a pair of symmetrically disposed longitudinally extending slits in the bottom end of each of said walls defining tabs and aps on said outer and inner tubes, the spacing of the slits in said inner tube being lesser than the spacing of the slits in said outer tube whereby said inner tube flaps are of a greater width than said outer tube flaps and said inner tube tabs are of a lesser width than said outer tube tabs, said inner tube flaps having bottom edges disposed beyond the bottom edges of said outer tube flaps to form projecting bottom portions, the projecting bottom portion of one of said inner tube iiaps being reversely folded over the bottom edge of an associated one of said outer tube flaps, upwardly diverting fold lines on each of said walls separating said flaps and tabs, said slits terminating at said fold line, said liaps being first folded towards each other, said outer tube iiaps each extending substantially half way across the length of the bag bottom, the projecting bottom portion of theA other of said inner tube flaps overlying said reversely folded bottom portion, said tabs extending more than half way across the width of the bag bottom in overlapping relation to each other and to said iiaps whereby said inner tube aps and tabs `are sealed to each other exclusive of said outer tube, and said outer tube iiaps and tabs overlie and project the joints between said inner tube llaps and tabs and all interior portions of the bag bottom are formed by said inner tube, upper edge portions of said inner tube aligned with said inner tube flaps terminating short of the upper edge of said outer tube, the omitted upper edge portions of said inner tube corresponding in shape and extent to said projecting bottom portions.

4. A bag formed -of a iiattened composite tube including at least an outer tube and an inner tube, said flattened composite tube having a pair of oppositely facing walls and a bottom end, a pair of symmetrically disposed longitudinally extending slits in the bottom end of each of said walls deiining tabs and flaps on said outer and inner tubes, the spacing of the slits in said inner tube being lesser than the spacing of the slits in said outer tube whereby said inner tube flaps are of a greater width than said outer tube flaps and said inner tube tabs are of a lesser width than said outer tube tabs, said inner tube flaps having bottom edges disposed beyond the bottom edges of said outer tube flaps to form projecting bottom portions, the projecting bottom portion of one of said inner tube flaps being reversely folded over the bottom edge of an associated one of said outer tube aps, upwardly diverting fold lines on each of said walls separating said flaps and tabs, said slits terminating at said fold line, said flaps being first folded towards each other, said outer tube iiaps each extending substantially half Way across the length of the bag bottom, the projecting bottom portion of the other of said inner tube aps overlying said reversely folded bottom portion, said tabs extending more than half way across the width of the bag bottom in overlapping relation to each other and to said flaps whereby said inner tube flaps and tabs are sealed to each other exclusive of said outer tube, and said outer tube flaps and tabs overlie and protect the joints between said inner tube flaps and tabs and all interior portions of the bag bottom are formed by said inner tube, upper edge portions of said inner tube aligned with said inner tube flaps terminating short of the upper edge of said outer tube, the omitted upper edge portions of said inner tube corresponding in shape and extent to said projecting bottom portions, said outer tube being formed from a rectangular blank, said inner tube being formed from a blank having substantially the same area as said outer tube blank.

5. A bag formed of a attened composite tube including atleast an outer tube and an inner tube, said flattened composite tube having a pair of oppositely facing walls and a bottom end, a pair of symmetrically disposed longitudinally extending slits in the bottom end of each of said wails defining tabs and iiaps on said outer and inner tubes, the spacing of the slits in said inner tube being lesser than the spacing of the slits in said outer tube whereby said inner tube flaps are of a greater width than said outer tube aps and said inner tube tabs are of a lesser width than said outer tube tabs, said inner tube iiaps having bottom edges disposed beyond the bottom edges of said outer tube flaps to form projecting bottom portions, the projecting bottom portion of one of said inner tube iiaps being reversely folded over the bottom edge of an associated one of said outer tube fiaps, upwardly diverting fold lines on each of said walls separating said flaps and tabs, said slits terminating at said fold line, said flaps being first folded towards each other, said outer tube flaps each extending substantially half way across the length of the bag bottom, the projecting bottom portion of the other of said inner tube iiaps overlying said reversely folded bottom portion, said tabs extending more than half way across the width of the bag bottom in overlapping relation to each other and to said flaps whereby said inner tube tiaps and tabs are sealed to each other exclusive of said outer tube, and said outer tube aps and tabs overlie and project the joints between said inner tube aps and tabs and all interior portions of the bag bottom are formed by said inner tube, said outer tube being formed from a rectangular blank, said inner tube being formed from a blank having substantially the same area as said outer tube blank, adhesive marginally sealing said blanks to each other prior to folding to form said inner and outer tubes.

6. A blank assembly for forming a bag of the type which includes an inner tube, an outer tube and a bottom and wherein the bottom has an inner portion formed entirely by the inner tube, said blank assembly comprising an inner tube forming blank and an outer tube forming blank, each of said blanks having parallel side edges, an upper edge and a bottom edge, said blanks being disposed in overlying relation, pairs of longitudinal slits in each of said blanks opening through said bottom edges and defining two iiaps and two tabs on each of said blanks, the spacing between slits of each pair of slits in said inner tube forming blank being greater than the spacing between like slits of said outer tube forming blank whereby said flaps of said inner tube forming blank are of a greater width than said iaps of said outer tube forming blank, the bottom edge of said inner tube forming blank along said ilaps being disposed beyond the bottom edge of said outer tube forming blank whereby said aps of said inner tube forming blank completely overlie said ilaps of said outer tube forming blank, said outer tube forming blank being rectangular, and said inner tube forming blank being substantially the same area as said outer tube forming blank.

7. A bag formed of a llattened composite tube including at least an outer tube and an inner tube, said flattened composite tube having a pair of oppositely facing walls and a bottom end, the bottom end of each of said walls including tabs and flaps on said outer and inner tubes, said inner tube flaps having bottom edges disposed beyond the bottom edges of said outer tube aps to form projecting bottom portions, the projecting bottom portion of one of said inner tube aps being reversely folded over the bottom edge of an associated one of said outer tube iiaps, said flaps being iirst folded toward each other, the projecting bottom portion of the other of said inner tube aps overlying said reversely folded bottom portion, said tabs extending across the bag bottom toward each other in overlapping relation to said iiaps whereby said inner tube flaps and tabs are sealed to each other exclusive of said outer tube, and said outer tube flaps and tabs overlying and protect the joints between said inner tube flaps and tabs and all interior portions of the bag bottom are formed by said inner tube.

8. A bag formed of a flattened composite tube including at least an outer tube and an inner tube, said iiattened composite tube having a pair of oppositely facing walls and a bottom end, the bottom end of each of said Walls including tabs and flaps on said outer and inner tubes, said inner tube flaps having bottom edges disposed beyond the bottom edges of said outer tube flaps to form projecting bottom portions, the projecting bottom portion of one of said inner tube flaps being reversely fol-ded over the bottom edge ot an associated one of said outer tube iiaps, said aps being rst folded toward each other, the projecting bottom portion of the other of said inner tube ilaps overlying said reversely folded bottom portion, said tabs extending across the bag bottom toward each other in overlapping relation to said iiaps whereby said inner tube flaps and tabs are sealed to each other exclusive of said outer tube, and said outer tube tiaps and tabs overlying and protect the joints between said inner `tube iiaps and tabs and all interior portions of the bag bottom are formed by said inner tube, upper edge portions of said inner tube aligned with said inner tube iiaps terminating short of the upper edge of said outer tube, the omitted upper edge portions of said inner tube corresponding in shape and extent to said projecting bottom portions.

9. A blank assembly for forming a bag of the type which includes an inner tube, an outer tube and a bottom and wherein the bottom has an inner portion formed entirely by the inner tube, said blank assembly comprising an inner tube forming blank and an outer tube forming blank, each of said blanks having parallel side edges, an upper edge and a bottom edge, said blanks being disposed in overlying relation, at least one pair of longitudinal slits in each of said blanks opening through said bottom edges and partially detining flaps and tabs on each of said blanks, the bottom edge of said inner tube forming blank along said flaps being disposed beyond the bottom edge of said outer tube forming blank whereby said tiaps of said inner tube forming blank project completely beyond said aps of said outer tube forming blank, said outer tube forming blank being rectangular, said inner tube forming blank being of substantially the same area as said outer tube forming blank, an upper edge portion of said inner tube terminating short of the upper edge of said outer tube and defining a slot corresponding in shape and extent to the portion of the inner tube forming blank disposed beyond the bottom edge of said outer tube forming blank, the portion of the inner tube forming blank disposed beyond the outer tube forming blank being robbed from the material of the next preceding blank during the manufacture thereof thereby deiining said slot and forming said disposed portion without the loss of material during the manufacture of the blank assembly, said inner and outer tube forming blanks being staggered only transversely to detine oiiset longitudinal edge portions, and the upper edges of said inner and outer tube forming blanks being devoid of flaps and tabs.

10. A blank assembly for forming a bag of the type which includes an inner tube, an outer tube and a bottom and wherein the bottom has an inner portion formed entirely by the inner tube, said blank assembly comprising an inner tube forming blank and an outer tube forming blank, each of said blanks having parallel side edges, an upper edge and a bottom edge, said blanks being disposed in overlying relation, at least one pair of longitudinal slits in each of said blanks opening through said bottom edges and partially defining a pair of flaps and at least one tab on each of said blanks, the bottom edge of said inner tube forming blank along said iiaps being disposed beyond the bottom edge of said outer tube forrn ing blank whereby said iiaps of said inner tube forming blank project completely beyond the iaps of said outer tube forming blank, said outer tube forming blank being generally rectangular, said inner tube forming blank being of substantially the same area as said outer tube forming blank, an upper edge portion of said inner tube forming blank terminating short of the upper edge of said outer tube forming blank and defining a slot corresponding in shape and extent to the portion of the inner tube forming blank disposed beyond the bottom edge of the outer tube forming blank, the portion of the inner tube blank disposed beyond the outer tube forming blank being robbed from the material of an adjacent blank during the manufacture thereof thereby defining said slot and forming said disposed portion without the loss of material during the manufacture of the blank assembly, said inner and outer tube forming blanks being staggered transversely to define oiiset longitudinal edge portions, the upper edges of said inner and outer tube forming blanks being devoid of flaps and tabs projecting beyond the upper edge of sai-d blank assembly, and adhesive means securing said inner and outer tube forming blanks together.

lll. A bag formed of a composite tube including at least an outer tube and an inner tube, said composite tube having upper and lower end portions, the lower end portion of said composite tube including a plurality of closure panels formed of the material of said outer and inner tubes, first and second closure panels of a first pair of said plurality of closure panels being folded toward each other in opposed relationship, third and fourth closure panels of a second pair of said plurality of closure panels being folded toward each other with said third closure panel being in overlying relationship to said iirst pair of closure panels and said fourth closure panel being in overlying relationship to both said third closure panel and said iirst pair of closure panels, a portion of the inner tube of the first pair of closure panels being disposed beyond a portion of the outer tube of the first pair of closure panels, said inner tube portions terminating in edge portions disposed beyond an associated edge portion of the outer tube at each of the first pair of closure panels, at least one of said third and' fourth closure panels having a pair of slits in each of the tubes delining a tab, said outer tube in the area of said tab terminating in an edge, said inner tube in the area of said tab terminating in an edge, said last-mentioned tab edges being in coincidence whereby none of the material of the inner tube projects beyond the material of the outer tube in a direction beyond the outer tube tab edge, said inner and outer tubes being of substantially the same area and volume, an upper edge portion of said inner tube terminating short of the upper edge of said outer tube at the upper end portion of said composite tube and at least partially defining a slot corresponding in shape and extent to the portion of the inner tube disposed beyond the outer tube at the first pair of closure panels, the portion of the inner tube disposed beyond the outer tube at the iirst pair of closure panels being robbed from the ma terial of the next adjacent blank during the manufacture thereof thereby partially dening said slot and forming said disposed portion without the loss of material during the manufacture of the bag, said inner and outer tubes having staggered longitudinal seams, the upper end portions of said inner and outer tubes being devoid of closure panels projecting beyond a terminal top end of the bag, and adhesive means securing said inner and outer tubes together.

12. A bag formed of a composite tube including at least an outer tube and an inner tube, said composite tube having upper and lower end portions, the lower end portion of said composite tube including a plurality of elosure panels formed of the material of said outer and inner tubes, first and second closure panels of a first pair of said plurality of closure panels being folded toward each other in opposed realtionship, third and fourth closure panels of a second pair of said plurality of closure panels being folded toward each other with said third closure panel being in overlying relationship to said first pair of closure panels and said fourth closure panel being in overlying relationship to both said third closure panel and said rst pair of closure panels, a portion of the inner tube of the first pair of closure panels being disposed beyond a portion of the outer tube of the first pair of closure panels, said inner tube portions terminating in edge portions disposed beyond an associated edge portion of the outer tube at each of the first pair of closure panels, at least one of said third and fourth closure panels having a pair of slits in each of the tubes defining a tab, said outer tube in the area of said tab terminating in an edge, said inner tube in the area of said tab terminating in an edge, the edge of the inner tube tab terminating short of the edge of the outer tube tab whereby the material of the outer tube tab projects beyond the material of the inner tube tab in a direction beyond the inner tube tab edge, said inner and outer tubes being of substantially the same area and volume, an upper edge portion of said inner tube terminating short of the upper edge of said outer tube at the upper end portion of said composite tube and at least partially defining a slot corresponding in shape and extent to the portion of the inner tube disposed beyond the outer tube at the first pair of closure panels, the portion of the inner tube disposed beyond the outer tube at the first pair of closure panels being robbed from the material of the next adjacent blank during the manufacture thereof thereby partially defining said slot and forming said disposed portion without the loss of material during the manufacture of the bag, said inner and .outer tubes having staggered longitudinal seams, the upper end portions of said inner and outer tubes being devoid of closure panels projecting beyond a terminal top end of the bag, and adhesive means securing said inner and outer tubes together.

13. A blank assembly for forming a bag of the type which includes an inner tube, an outer tube and a bottom and wherein the bottom has an inner portion formed entirely by the inner tube, said blank assembly comprising an inner tube forming blank and an outer tube forming blank, each of said blanks having parallel side edges, an upper edge and a bottom edge, said blanks being disposed in overlying relation, at least one pair of longitudinal slits in each of said blanks opening through said bottom edges to define at least one tab on each of said blanks, said tabs being in opposed overlying relationship to define a composite tab formed of the material of said inner and outer tube forming blanks, a plurality of fold lines defining a plurality of closure panels, said closure panels including a first pair of closure panels including first and second closure panels adapted for folding toward one another into opposed relationship in a bag formed from the blank assembly, third and fourth closure panels being similarly adapted for folding along associated ones of said fold lines during the formation of said bag, the bottom edge of said inner tube forming blank along at least said first and second closure panels being disposed beyond associated edges of the outer tube forming blank at said rst and second closure panels whereby the material of the inner tube forming blank along the first and second closure panels is disposed beyond the material of the outer tube forming blank at the first and second closure panels, said outer tube forming blank being generally rectangular, said inner tube forming blank being of substantially the same area as said outer tube forming blank, an upper edge portion of said inner tube forming blank terminating short of the upper edge of lsaid outer tube forming blank and at least partially defining a slot corresponding in shape and extent to the portions of the inner tube forming blank disposed beyond the bottom edge of said outer tube forming blank at said first and second closure flaps, the portions of the inner tube forming blank disposed beyond the outer tube forming blank being robbed from the material of an adjacent blank during the manufacture thereof thereby at least partially defining said slot and forming said disposed portions without the loss of material during the manufacture of the blank assembly, said inner and outer tube forming blanks being staggered transversely to define offset longitudinal edge portions, said tab forming a portion of said fourth closure panel, adhesive means securing said inner and outer tube forniing blanks together, and the upper edges of said inner and outer tube forming blanks being devoid of closure panels projecting beyond the top edge of said blank assembly.

References Cited by the Examiner UNITED STATES PATENTS 1,960,929 5/1934 Taggart 229-55 2,078,467 4/ 1937 Sterling 229-55 X 2,377,005 5/ 1945 Haslacher 229-55 X 2,420,212 5/ 1947 Volksdorf 229-55 2,460,886 2/ 1949 Hoppe 229-59 2,600,487 6/ 1952 Craig 229-59 2,751,141 6/1956 Owens 229-55 2,810,509 10/1957 Gelbcke 229-55 2,875,944 3/ 1959 Duflin 229-55 FOREIGN PATENTS 330,607 10/1935 Italy.

GEORGE O. RALSTON, Primary Examiner. 

1. A BAG FORMED OF A FLATTENED COMPOSITE TUBE INCLUDING AT LEAST AN OUTER TUBE AND AN INNER TUBE, SAID FLATTENED COMPOSITE TUBE HAVING A PAIR OF OPPOSITELY FACING WALLS AND A BOTTOM END, A PAIR OF SYMMETRICALLY DISPOSED LONGITUDINALLY EXTENDING SLITS IN THE BOTTOM END OF EACH OF SAID WALLS DEDINING TABS AND FLAPS ON SAID OUTER AND INNEER TUBES, THE SPACING OF THE SLITS IN SAID INNER TUBE BEING LESSER THAN THE SPACING OF THE SLITS IN THE OUTER TUBE WHEREBY SAID INNER TUBE FLAPS ARE OF A GREATER WIDTH THAN SAID WIDTH TUBE FLAPS AND SAID INNER TUBE TABS ARE OF A LESSER WIDTH THAN SAID OUTER TUBE TABS, SAID INNER TUBE FLAPS HAVING BOTTOM EDGES DISPOSED BEYOND THE BOTTOM EDGES OF SAID OUTER TUBE FLAPS TO FORM PROJECTING BOTTOM PORTIONS, THE PROJECTING BOTTOM PORTION OF ONE OF SAID INNER TUBE FLAPS BEING REVERSELY FOLDED OVER THE BOTTOM EDGE OF AN ASSOCIATED ONE OF SAID OUTER TUBE FLAPS, UPWARDLY DIVERGING FOLD LINES ON EACH OF SAID WALLS SEPARATING SID FLAPS AND TABS, SAID SLITS TERMINATING AT SAID FOLD LINE, SAID FLAPS BEING FIRST FOLDED TOWARDS EACH OTHER, SAID OUTER TUBE FLAPS EACH EXTENDING SUBSTANTIALLY HALF WAY ACROSS THE LENGTH OF THE BAG BOTTOM, THE PROJECTING BOTTOM PORTION OF THE OTHER OF SAID INNER TUBE FLAPS OVERLYING SAID REVERSELY FOLDED BOTTOM 